Large gate valves are commonly used in a wide range of applications, including mining, manufacturing, refining, sewer and water, and many others. In many of these applications, such as the use of large gate valves in the transportation of water, the valves can remain in use for many years, and even decades, with relatively little significant maintenance or service. However, many other large gate valves are often used in extremely challenging environments where the interior surfaces of the valve components are exposed to abrasive or corrosive materials that can rapidly degrade all but the most durable of materials. For example, carrying of mining slurries with significant amounts of rock and sand can wear away interior valve components rapidly. Similarly, tar sands, such as those mined in western Canada for fuel, are processed at elevated temperatures and with very high solids contents that readily degrade the interior of valves as they pass through.
In order to promote longer service life of valves, especially large gate valves that operate in extreme conditions, it is possible to create replaceable surfaces that line portions of the inside of the valves. These replaceable surfaces can be made of much harder materials than the other valve components—in part because they require less elaborate machining than other parts, and also because they can use higher priced metals without requiring such materials throughout the valve. In addition, the removable nature of the replaceable surface allows them to be replaced without replacing or rebuilding the entire valve.
Unfortunately, one challenge of existing gate valve designs is that it can be difficult to replace the wear surfaces because existing systems for installing, retaining, and removing the wear surfaces have significant shortcomings. Therefore, a need exists for an improved valve design that allows for the easy installation of wear surfaces, for the secure retention of the wear surfaces, and the efficient and easy removal and replacement of the wear surfaces when desired.